Melt-blown nonwoven fabric

ABSTRACT

A melt-blown nonwoven fabric of the present invention is formed from an ethylene-(meth)acrylic acid copolymer having a melt flow rate of 50 to 1000 g/10 min measured at 2.16 kg load and at a temperature of 190° C. in accordance with ASTM D1238, and a content of acrylic acid or methacrylic acid unit of 2 to 25 weight %. The nonwoven fabric has the sum of values of (tensile strength (g/5 cm))/(basis weight (g/m 2 )) in machine direction and cross direction of 30 to 100, and a residual strain after 50% extension of no more than 20%, and is excellent in gas permeability , elasticity and moreover moderate strength. The nonwoven fabric is suitable for elasticized fabric components, packaging materials, laminates, etc.

TECHNICAL FIELD

[0001] The present invention relates to a melt-blown nonwoven fabric,and particularly to a melt-blown nonwoven fabric suitable forelasticized fabric components, packaging materials, laminates, etc.having outstanding gas permeability, elasticity as well as moderatestrength.

BACKGROUND ART

[0002] In recent years, nonwoven fabrics have been used for variouskinds of applications, and their applications have also been expanding.And demands for various characteristics are now increasing in accordancewith the uses. For example, excellent elasticity with outstanding gaspermeability is required, based on the parts used, in nonwoven fabricsused for gathers of disposable diapers, a part of medical supplies, suchas sanitary napkins, base cloths of wet compress, etc. Moreover,moderate strength is also required in them upon their processing andmolding processes.

[0003] Porous films of polyvinyl chroride are conventionally used asmaterials such as poultice medicine base cloths etc. that are attachedto a human body using elasticity. However these materials induce aproblem of dioxin generation when they are wasted and burned. Althoughpolyurethane melt-blown nonwoven fabrics are provided into market as areplacement of polyvinyl chloride, this material is expensive and alsohas a problem of harmful gas generation at the time of combustion.

[0004] For these reasons, a melt-blown nonwoven fabric that has amoderate strength while having outstanding gas permeability andelasticity and is made from a material with little environmental burdenhas been required. A melt-blown nonwoven fabric excellent inprintability, low-temperature heat seal property and hot tack propertyhas also been required.

[0005] An objective of the present invention is to provide a melt-blownnonwoven fabric that gives little burden on the environment while havingoutstanding gas permeability and elasticity as well as moderatestrength, and that is comparatively economical and advantageous in cost.Moreover, the other objective of the present invention is to provide amelt-blown nonwoven fabric excellent in printability, low-temperatureheat. seal property and hot tack property.

DISCLOSURE OF THE INVENTION

[0006] As a result of wholehearted examination made by the presentinventors in order to solve the above-mentioned problems, it was foundout that a melt-blown nonwoven fabric made from ethylene-(meth)acrylicacid copolymers solves above described problems, and the presentinvention was attained. In the present invention, (meth)acrylic acidrepresents acrylic acid or methacrylic acid, and ethylene-(meth)acrylicacid copolymers represent ethylene-acrylic acid copolymers orethylene-methacrylic acid copolymers.

[0007] That is, according to the present invention, a melt-blownnonwoven fabric made from ethylene-(meth)acrylic acid copolymers isprovided.

[0008] In a preferred embodiment of the above-mentionedethylene-(meth)acrylic acid copolymers, the copolymers preferably have amelt flow rate of 50 to 1000 g/10 min measured at 2.16 kg load and at atemperature of 190° C. in accordance with ASTM D1238, and 2 to 25 weight% of (meth)acrylic acid unit content.

[0009] In a preferred embodiment of the above-mentioned melt-blownnonwoven fabric, the sum of values of tensile strength (g/5 cm) /basisweight (g/m²) in machine direction and cross direction is preferably 30to 100, and tensile elongation in machine direction and cross directionis 80% or higher each.

[0010] Moreover, in a preferred embodiment of the above-mentionedmelt-blown nonwoven fabric, a residual strain after 50% extension ispreferably 20% or less, and a residual strain after 100% extension is nomore than 50%.

[0011] An elasticized fabric component and packaging material comprisingthe above-mentioned melt- blown nonwoven fabric, and a nonwoven fabriclaminate having at least one layer of the above-mentioned melt-blownnonwoven fabric are provided by the present invention.

[0012] A manufacturing method of the above-mentioned melt-blown nonwovenfabric is preferably a melt-blowing method in whichethylene-(meth)acrylic acid copolymer is directly extruded frommelt-blowing dies located in a line into two flows of high-speed,high-temperature converging air streams , and then the molten copolymeris drawn, made finer and collected onto a conveying screen. In thisprocess air flow per 1 kg of above-mentioned copolymer is preferably 10to 200 Nm³ and a distance from melt-blowing dies to a collection screenis preferably 10 to 40 cm.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] A description about a melt-blown nonwoven fabric of the presentinvention and its manufacturing method will concretely be givenhereinafter.

[0014] A melt-blown nonwoven fabric (henceforth, referred to as amelt-blown nonwoven fabric of the present invention) of the presentinvention is made from ethylene-(meth)acrylic acid copolymers.

[0015] The ethylene-(meth)acrylic acid copolymers are copolymers inwhich ethylene is copolymerized with acrylic acid or methacrylic acidand, if necessary, further unsaturated carboxylic acid esters by awell-known radical polymerization method etc., and contain a unit ofacrylic acid or methacrylic acid of preferably 2 to 25 weight %, morepreferably 5 to 20 weight %, and still more preferably 10 to 15 weight %in a polymer. When a content of acrylic acid or methacrylic acid unit isin this range, good touch and flexibility as well as good elasticity,chemical resistance, solvent resistance, hot tack property, heat sealproperty, and printability, and also an advantage in cost are obtained.Moreover, an extrusion temperature in the range of from 160 to 280° C.is suitable, and it has an advantage that the ethylene-(meth)acrylicacid copolymers may be extruded at a higher temperature(e.g. 240° C. ormore) than ethylene-vinyl acetate copolymers.

[0016] Besides, if an unsaturated carboxylic acid ester unit exists inthe ethylene-(meth)acrylic acid copolymers, it improves flexibility, andits content usually ranges 0 to 25 weight %, and preferably 0 to 15weight %, and more preferably 0 to 10 weight %. As unsaturatedcarboxylic acid esters, alkyl esters with 1 to 8 carbons of(meth)acrylic acid are preferable, and, specifically, methyl acrylate,methyl methacrylate, ethyl acrylate, ethyl methacrylate, iso-propylacrylate, iso-propyl methacrylate, n-butyl acrylate, n-butylmethacrylate, iso-butyl acrylate, iso-butyl methacrylate, 2-ethylhexylacrylate, and 2-ethylhexyl methacrylate etc. may be mentioned.

[0017] Besides, a melt flow rate (MFR) of the ethylene-(meth)acrylicacid copolymers, measured under the conditions of 2.16 kg load at atemperature of 190° C., in accordance with ASTM D1238 is preferably 50to 1000 g/10 min, more preferably 100 to 500 g/10 min. If an MFR valueis within the range, a phenomonon of generating of scattering of fiberwaste (fly) and resin lump (shot) that often pose problems inmelt-blowing methods is hardly observed, and it becomes easy to makefibers finer.

[0018] In the present invention in order to improve tensile elongationof a melt-blown nonwoven fabric, thermoplastic polymers selected fromethylene-a-olefin random copolymers, ethylene-vinyl acetate copolymers,ethylene-(meth)acrylate copolymers, styrene-conjugated diene-styreneblock copolymers and hydrogenated styrene-conjugated diene-styrene blockcopolymers may be blended to ethylene-(meth)acrylic acid copolymers.These thermoplastic polymers may be blended in an amount of 0 to 100weight parts, preferably 0 to 40 weight parts, more preferably 0 to 10weight parts to ethylene-(meth)acrylic acid copolymers of 100 weightparts.

[0019] In the above-mentioned ethylene-a-olefin random copolymers, it ispreferable to use copolymers with a density of 870 to 940 kg/m³ andespecially of 880 to 930 kg/m³. Besides, as α-olefins in the copolymers,α-olefins with 3 to 12 carbons, such as propylene, 1-butene, 1-pentene,1-hexene, 1-octene, 1-decene, 1-dodecene, and 4-methyl-1-pentene may bementioned. Such ethylene-α-olefin random copolymers may be manufacturedwith single-site catalysts or with multi-site catalysts.

[0020] As the above-mentioned ethylene-vinyl acetate copolymers, vinylacetate unit is preferably 5 to 40 weight %, and especially preferably10 to 30 weight %. Besides,. as the above-mentionedethylene-(meth)acrylate copolymers, (meth)acrylic acid ester unit ispreferably 5 to 40 weight %, and especially preferably 10 to 30 weight%. What is already mentioned may be used here as (meth)acrylic acidesters. These copolymers may be obtained by a radical copolymerizationunder a condition of high temperature and high pressure.

[0021] As the above-mentioned ethylene-α-olefin copolymers,ethylene-vinyl acetate copolymers and ethylene-(meth) acrylatecopolymers, an MFR based on 190° C. and 2.16 kg load of 1 to 100 g/10min are preferable, and that of 10 to 500 g/10 min are more preferable.

[0022] As conjugated dienes in the above-mentioned styrene-conjugateddiene-styrene block copolymers, and hydrogenated copolymers of them,butadiene or isoprene is preferable. Besides, in styrene-conjugateddiene-styrene block copolymers, conjugated dienes are polymerized by1,2-polymerization, 1,4-polymerization, 3,4-polymerization, or bypolymerization in the combination of these polymerizations. In thecopolymers, a styrene unit preferably accounts for the range of 8 to 50weight %, especially 10 to 40 weight %. Besides, in the above-mentionedhydrogenated polymers, conjugated diene units are preferablyhydrogenated by 70% or more, more preferably by 90% or more. Asstyrene-conjugated diene-styrene block copolymers, and theirhydrogenated copolymers, copolymers that have an MFR at 230° C. and 2.16kg load of 1 to 200g/10 min are preferably used, and that have an MFR of2 to 100 g/10 min are more preferably used.

[0023] In the present invention, other resins may be added to theabove-mentioned ethylene-(meth)acrylic acid copolymers and theabove-mentioned thermoplastic polymers needed to be blended, in a rangein which the objectives of the present invention are not impaired. Asother resins that may be added, for example; polyethylenes (highpressure low density polyethylenes, middle or high-densitypolyethylenes, etc.), polypropylenes (homopolymers, random copolymersand block copolymers with other a-olefins), polyethylene terephthalates,polyester elastomers, polyamides (nylon), polyurethanes, polyvinylalcohol, ethylene-(meth)acrylic acid copolymer ionomers, andpolystyrenes etc. may be mentioned.

[0024] In the present invention, pigments, heat stabilizers, lubricants,nuclear agents, etc. may be blended into the above-mentionedethylene-(meth)acrylic acid copolymers in a range in which the objectiveof the present invention are not impaired.

[0025] A melt-blown nonwoven fabric made from the above-mentionedethylene-(meth)acrylic acid copolymers can be made by a conventionalmelt-blowing method where ethylene-(meth)acrylic acid copolymer isdirectly extruded from melt-blowing dies located in a line into twoflows of high-speed, high-temperature converging air streams and thenthe molten copolymer is drawn, made finer and collected onto a conveyingscreen.

[0026] In this case, air flow per 1 kg of the above-mentioned copolymeris 10 to 200 Nm³ and more preferably 20 to 150 Nm³. If the amount of airflow in this range is used, the diameter of fiber becomes moderatelysmall and an aggravation of physical properties does not happen. Inaddition, a fly phenomenon that often occurs when air flow is excessiveis not observed, and troubles in production may be avoided.

[0027] Moreover, the distance from the melt-blowing dies to thecollective screen is preferably 10 to 40 cm, and more preferably 15 to25 cm. If this distance is within this range, a surface of nonwovenfabric becomes smooth, and a poor appearance caused by fiber bundles isavoidable. Moreover, tensile strength reaches a satisfactory level.

[0028] Furthermore, a nonwoven fabric web formed by the melt-blowingmethod is preferably thermal-bonded in parts by emboss processing. Whenemboss processing is carried with the embossed part in perfect moltenstate, a thermal-bonded area (equivalent to stamping area of theembossing roll) is preferably 1 to 50% of the overall nonwoven fabricarea, and when emboss processing is carried out with the embossed partin half-molten state (to maintain fiber shape), a thermal-bonded area ispreferably 10 to 100% of the overall nonwoven fabric area. If apercentage of thermal-bonded area is in this range, soft touch ofmelt-blown nonwoven fabric is maintained and tensile strength andabrasion resistance are improved.

[0029] A basis weight of a melt-blown nonwoven fabric of the presentinvention obtained as mentioned above is preferably 5 to 200 g/m², andmore preferably 30 to 100 g/m². Moreover, an average diameter of fiberof a melt-blown nonwoven fabric is preferably 5 to 20 micrometers.

[0030] A description about tensile characteristics of a melt-blownnonwoven fabric of the present invention is given below.

[0031] The sum of values of (tensile strength)/(basis weight) obtainedby dividing tensile strength (g/5 cm) by basis weight (g/m²) of nonwovenfabric in machine direction and in cross direction is preferably 30 to100, more preferably 50 to 100.

[0032] Tensile elongation in each of machine direction and crossdirection is preferably 80% or more, and more preferably 100% or more.

[0033] In the present invention, “machine direction (MD)” means adirection of flow of nonwoven fabric in nonwoven fabric fabricatingoperation, and “cross direction (CD)” means a transverse direction inthe direction of the flow of the nonwoven fabric.

[0034] Moreover, in machine direction and cross direction, a residualstrain after 50% extension is preferably 20% or less, more preferably15% or less, and a residual strain after 100% extension is preferably50% or less, and more preferably 35% or less. A residual strain afterextension here means a percentage of a length of a sample extended to anoriginal length of the sample, in which a nonwoven fabric sample iselongated to a predetermined elongation and immediately returned to theoriginal position at the same elongation/shrinking speeds.

[0035] Since a melt-blown nonwoven fabric of the present invention hassuch tensile characteristics as well as excellent elasticity and gaspermeability, and moderate strength, it is extremely excellent as anonwoven fabric for elasticized fabric components, and can be used as abase cloth for plasters, wet compress and poultice medicines etc.; bodypersonal protective equipments such as supporters, sacks, and bandages;elastic components for surgical goods of masks, caps, shoes covers,etc.; elastic components for health goods of disposable diapers,sanitary napkins, etc. A melt-blown nonwoven fabric of the presentinvention may also be used as packaging materials such as; for example,gas permeable packaging materials for insecticides/fungicides,deodorants/odorants, oxygen absorbents, chemical body warmers, perfumes,sweets, and fruits; packaging materials for medical goods (syringesetc.) sterilizable with glycerol; or water permeable packaging materialsfor tea, green tea, coffee, agricultural chemicals, water pigment, andink.

[0036] Furthermore, since a melt-blown nonwoven fabric of the presentinvention has flexibility, good chemical resistance, solvent resistance,and touch, moderate strength and an outstanding printability, it maysuitably be used as a nonwoven fabric laminate that has at least onelayer of the melt-blown nonwoven fabrics. Specifically, the laminatescan be used for disposable garments (under wears, work wears, surgicalgowns and masks), and interior materials for curtains and tablecloths.In such laminates, various films, textiles, nonwoven fabrics, cottoncloths, nets, tallies, synthetic paper, etc. may be selected asmaterials to make laminates with a melt-blown nonwoven fabric of thepresent invention.

[0037] Specifically, they are films of thermoplastic polymers such asolefin polymers like polyethylene, polypropylene,poly-4-methyl-1-pentene, ethylene-vinyl acetate copolymers, orpolyesters and polyamides, and textiles, nonwoven fabrics, cottoncloths, nets, tallies, synthetic paper, etc. which are comprised fromfibers of above-mentioned thermoplastic polymers, regenerated fibersand/or natural fibers. The above-mentioned films may or may not beoriented, and moreover, may be non-porous films or porous films.Moreover, the above-mentioned nonwoven fabric obtained by variousmethods may be used. For example, a nonwoven fabric manufactured bymethods, such as spun-bonding method, melt-blowing method, dry processmethod, and wet process method, may be used.

EXAMPLES

[0038] Hereinafter, although a description of the present invention isgiven in detail by referring to Examples, the present invention is notlimited to these Examples.

[0039] Measurements of a ratio of (tensile strength)/(basis weight),tensile elongation, a residual strain after extension, and the diameterof a fiber, evaluations of appearance, touch, strength of hot tack andheat seal strength in the following Examples were performed according tothe following methods.

[0040] (1) (Tensile Strength)/(Basis Weight) and Tensile Elongation

[0041] A nonwoven fabric specimen with a width of 5 cm was held in 100mm of distance between chucks of a tension tester and tensile test wasperformed under a condition of elongation speed of 100 mm/min at roomtemperature. Maximum strength (g) obtained by this test was defined astensile strength (g/5 cm), and maximum elongation was defined as tensileelongation. Measurement was performed in two directions of machinedirection (MD) and cross direction (CD). A value of tensile strength ineach direction was divided by basis weight (g/m²) of nonwoven fabricspecimen and a value of (tensile strength)/(basis weight) wascalculated.

[0042] (2) Residual Strain after Extension

[0043] A nonwoven fabric specimen with a width of 5 cm was held in 100mm of distance between chucks of the tension tester as described in thetensile test, under a condition of elongation speed of 100 mm/min atroom temperature. The specimen was elongated up to 50% or 100%, and thenreturned at the same elongation/shrinking speed to a point where thestress reached 0. The percentage of a length of the specimen elongatedand that of relaxed was defined as a residual strain. Measurement wasperformed in two directions of machine direction (MD) and crossdirection (CD).

[0044] (3) Diameter of a Fiber

[0045] The diameter of fiber was an average of 30 fibers selected atrandom where each measurement was done using photographs of ×500magnification by an electron microscope.

[0046] (4) Appearance

[0047] Visual observation of the nonwoven fabric was carried out, andexistence of fiber bundle was evaluated. A mark of ◯ was given when nofiber bundle was observed, and x was given when fiber bundle was clearlyobserved.

[0048] (5) Touch

[0049] A sensory evaluation by 10 panels was performed. Nonwoven fabricsample was touched to skin of evaluators, and the skin was rubbedlightly with the sample. A mark of ◯ was given when seven or more panelsjudged that the sample had a smooth touch and no coarse touch, and x wasgiven when other evaluation was given.

[0050] (6) Hot-Tack Strength

[0051] After a sample was heat sealed with heat seal pressure of 0.28MPa and for heat seal time of one second, hot-tack strength wasdetermined as the peel strength at a rate of 1000 mm/min after 0.375seconds of the one second heat seal.

[0052] (7) Heat Seal Strength

[0053] After a sample was heat sealed by one side heating with heat sealpressure of 0.2 MPa and for heat seal time of 2 seconds, heat sealstrength was determined as the peel strength at a rate of 300 mm/min.

EXAMPLE 1

[0054] An ethylene-methacrylic acid copolymer (MFR: 100 g/10 min,measured at 2.16 kg load and at temperature of 190° C. based on ASTMD1238 (the following MFR measurement uses the same conditions),methacrylic acid unit content: 11 weight %) was melted in an extruder atan extrusion temperature of 250° C. The obtained molten material wasextruded into high-speed, high-temperature air stream throughmelt-blowing dies, and collected on a collecting screen, and thus amelt-blown nonwoven fabric of 13 micrometers in diameter of a fiber anda basis weight of 40 g/m² was manufactured. At this time, an amount ofair flow per 1 kg of above-mentioned copolymer was 65 Nm³, and thedistance (collection distance) from the melt-blowing dies to thecollection screen was 25 cm.

[0055] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 1.

EXAMPLE 2

[0056] A melt-blown nonwoven fabric of 12 micrometers in diameter of afiber and a basis weight of 40 g/m² was manufactured as in Example 1except the change of the amount of air flow per 1 kg of copolymer to 120Nm³.

[0057] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 1.

EXAMPLE 3

[0058] An ethylene-methacrylicacidcopolymer (MFR: 300 g/10 min,methacrylic acid unit content: 20 weight %) was melted in the extruderat an extrusion temperature of 190° C. Obtained molten material wasextruded into high-speed, high-temperature air stream through themelt-blowing dies, and collected on the collecting screen, and thus amelt-blown nonwoven fabric of 8 micrometers in diameter of a fiber and abasis weight of 40 g/m² was manufactured. At this time, the amount ofair flow per 1 kg of above-mentioned copolymer was 120 Nm³, and thedistance (collection distance) from the melt-blowing dies to thecollection screen was 25 cm.

[0059] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 1.

EXAMPLE 4

[0060] An ethylene-methacrylic acid copolymer (MFR: 500 g/10 minutes,methacrylic acid unit content: 20 weight %) was melted in the extruderat an extrusion temperature of 170° C. The molten material obtained wasextruded into high-speed, high-temperature air stream through themelt-blowing dies, and collected on the collecting screen, and thus amelt-blown nonwoven fabric of 7 micrometers in diameter of fiber and abasis weight of 40 g/m² was manufactured. At this time, the amount ofair flow per 1 kg of above-mentioned copolymer was 120 Nm³, and thedistance (collection distance) from the melt-blowing dies to thecollection screen was 25 cm.

[0061] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 1.

REFERENTIAL EXAMPLE 1

[0062] A melt-blown nonwoven fabric of 7 micrometers in diameter of afiber and a basis weight of 40 g/m² was manufactured as in Example 4except the change of the amount of air flow per 1 kg of copolymer to 200Nm³, and the change of the collection distance to 45 cm.

[0063] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 1. TABLE 1 Referential ExampleExample 1 2 3 4 1 Tensile (MD/ 60/24 50/22 57/25 58/22 20/15 strength/CD) basis (MD + 84 72 82 80 35 weight CD) Tensile elongation 125/150116/106 133/175 120/165 55/63 (MD/CD) % Residual strain after 11/1113/15 11/11 12/11 68/52  50% extension (MD/CD) % Residual strain after27/27 35/32 28/26 32/28 fractured 100% extension (MD/CD) % Appearance ∘∘ ∘ ∘ x Touch ∘ ∘ ∘ ∘ ∘

EXAMPLE 5

[0064] The melt-blown nonwoven fabric (basis weight 40 g/m²) made fromethylene-methacrylic acid copolymer in Example 1 was adhered tocommercially available OPP film (biaxially oriented polypropylene film,thickness of 20 micrometers) by a polyurethane adhesive. Hot tack andheat seal strength of the nonwoven fabric face were measured. Resultsare shown in Table 2 and 3, respectively. As shown in Tables, themelt-blown nonwoven fabric of ethylene-methacrylic acid copolymerobtained exhibits an outstanding hot tack property and low-temperatureheat seal property, and therefore, is useful as an inner layer ofpackaging bags which are heat sealed.

COMPARATIVE EXAMPLES 1, 2

[0065] The melt-blown nonwoven fabric (basis weight 40 g/m²) made fromethylene-methacrylic acid copolymer in Example 5 was replaced with apolypropylene melt-blown nonwoven fabric (Mitsui Chemicals Co., LTD.SYNTEX V3040 NIE) of basis weight 40 g/m², or a polypropylenespun-bonded nonwoven fabric. (Mitsui Chemicals SYNTEX PS-108) of basisweight 40 g/m², and the two fabrics were adhered onto an OPP film as inExample 5. Hot tack and heat seal strength of each nonwoven fabric facewere measured. Results are shown in Table 2 and Table 3, respectively.

[0066] As shown in Tables, the melt-blown nonwoven fabric ofpolypropylene and the spun-bonded nonwoven fabric of polypropylene areinferior to the melt-blown nonwoven fabric of ethylene-methacrylic acidcopolymer, as an inner layer of packaging bags to be heat sealed. TABLE2 Measurement Hot tack strength (N/25 mm) temperature ComparativeComparative (° C.) Example 5 Example 1 Example 2 90 1.2 below 0.1 below0.1 100 1.4 below 0.1 below 0.1 110 1.1 below 0.1 below 0.1 120 0.9below 0.1 below 0.1 140 — 0.2 below 0.1 150 — 0.1 below 0.1 160 0.1below 0.1 below 0.1

[0067] TABLE 3 Measurement Heat seal strength (N/25 mm) temperatureComparative Comparative (° C.) Example 5 Example 1 Example 2 90 1.80 notadhered not adhered 100 5.15 not adhered not adhered 110 7.95 notadhered not adhered 120 8.75 not adhered not adhered 140 — 0.65 notadhered 150 — 1.25 not adhered 160 0.1 0.95 9.55

EXAMPLE 6

[0068] A melt-blown nonwoven fabric (MB) of ethylene-methacrylic acidcopolymer (10 g/m²) was prepared as in Example 1, except the change ofthe amount of air flow per 1 kg of copolymer to 150 Nm³, and a basisweight is adjusted to 10 g/m² in Example 1. This melt-blown nonwovenfabric was laminated with a spun-bonded nonwoven fabric (PE SB) madefrom polyethylene of basis weight of 30 g m² (STRAMIGHTY MN made byIdemitsu Petrochemical Co., LTD) by an embossing roll at 70° C.Evaluation of touch of the face of the ethylene-methacrylic acidcopolymer melt-blown nonwoven fabric in this laminate was performed.Result is shown in Table 4. Moreover, surface tension of this nonwovenfabric face was measured in order to determine printing characteristics.The result is also shown in Table 4.

[0069] These evaluations show that a nonwoven fabric of being excellentin touch, wettability, and printability may be obtained by the use ofmelt-blown nonwoven fabric made from ethylene-methacrylic acid copolymerin one layer of nonwoven fabric laminates.

COMPARATIVE EXAMPLES 3 and 4

[0070] Results of evaluation of touch and surface tension for aspun-bonded nonwoven fabric (PE SB) made from polyethylene of basisweight 30 g/m² (STRAMIGHTY MN made by Idemitsu Petrochemical Co., LTD),and a propylene spun-bonded nonwoven fabric (PP MB) (Mitsui ChemicalsCo., LTD. SYNTEX PS- 108) of basis weight 40 g/m² are shown in Table 4.TABLE 4 Surface tension Nonwoven fabric Touch (mN/m) Example 6 CopolymerMB/PE SB ∘ 41 laminated Comparative PE SB (spun-bonded) x 34 example 3Comparative PP MB (melt-blown) x 32 example 4

EXAMPLE 7

[0071] Ethylene-1-butene random copolymer (Mitsui Chemicals, Inc. TafmerA70090, density 890 kg/m³) 20 weight % was dry blended withethylene-methacrylic acid copolymer (MFR: 500 g/10 min, methacrylic acidunit content: 10 weight %) 80 weight %, and melt blended in an extruder.The molten mixture obtained was extruded into high-speed ,high-temperature air stream from the melt-blowing dies, and collected onthe screen to manufacture a melt-blown nonwoven fabric of 12 micrometersin diameter of a fiber and a basis weight of 40 g/m². At this time, theamount of air flow per 1 kg of the resin was 27 Nm³, and the distancefrom the melt-blowing dies to the collection screen 15 was 15 cm.

[0072] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 5.

EXAMPLE 8

[0073] A melt-blown nonwoven fabric with 13 micrometers in diameter of afiber and a basis weight of 40 g/m² was manufactured by the same methodas Example 7, except the change of using the ethylene-methacrylic acidcopolymer of Example 7 by 80 weight %, and a hydrogenatedstyrene-butadiene-styrene block copolymer (Asahi Kasei Corporation,Tuftec H1031) by 20weight %, and the change of the amount of spinningair flow to 44 Nm³ per 1 kg of the blend. Measurement and evaluationresults of the obtained melt-blown nonwoven fabric are shown in Table 5.

EXAMPLE 9

[0074] A melt-blown nonwoven fabric with 10 micrometers in diameter of afiber and a basis weight of 40 g m² was manufactured by the same methodas Example 7, except the change of using 80 weight % of theethylene-methacrylic acid copolymer of Example 7 and 20 weight % of anethylene-vinyl acetate copolymer (Du Pont-Mitsui Polychemicals Co.,Ltd., EVAFLEX V577), and the change of the amount of spinning air flowto 15 Nm³ per 1 kg of the blend.

[0075] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 5.

EXAMPLE 10

[0076] A melt-blown nonwoven fabric with 11 micrometers in diameter of afiber and a basis weight of 40 g/m² was manufactured by the same methodas Example 7, except the change of using 80 weight % of theethylene-methacrylic acid copolymer of Example 7, and 20 weight % of anethylene-ethyl acrylate copolymer (MFR: 275 g/10 min, ethyl acrylateunit content: 25 weight %) , and the change of the amount of spinningair flow to 27 Nm³ per 1 kg of the blend.

[0077] Measurement and evaluation results of the obtained melt-blownnonwoven fabric are shown in Table 5. TABLE 5 Example 7 8 9 10 Tensile(MD/ 23/17 23/19 21/16 21/17 strength/ CD) basis (MD + 40 42 37 38weight CD) Tensile elongation 205/220 380/400 210/200 200/205 (MD/CD) %Residual strain after 100% extension 28/28 28/26 30/30 28/28 (MD/CD) %

[0078] Industrial Applicability

[0079] Since a melt-blown nonwoven fabric of the present invention isexcellent in elasticity, gas permeability and moderate strength, it isexcellent as nonwoven fabric for elasticized fabric components, and canpreferably be applicable for base cloths for adhesive bandages,fomentation poultice; supporters, sacks, bandages; surgical masks, caps,shoe covers; disposable diapers, sanitary napkins, etc. A melt-blownnonwoven fabric of the present invention can also be applicable forpackaging materials and nonwoven fabric laminates.

[0080] Moreover, a melt-blown nonwoven fabric of the present inventiondoes not usually cause a problem of harmful gas generation when it iswasted and burned, and therefore, has little burden on the environment.

1. A melt-blown nonwoven fabric formed from an ethylene-(meth)acrylicacid copolymer.
 2. The melt-blown nonwoven fabric of claim 1, whereinsaid ethylene (meth)acrylic acid copolymer has a melt flow rate in therange of from 50 to 1000 g/10 min, measured at 2.16 kg load at atemperature of 190° C. in accordance with ASTM D1238 and a content ofacrylic acid or methacrylic acid unit in the range of from 2 to 25weight %.
 3. The melt-blown nonwoven fabric of claim 1, wherein saidethylene (meth)acrylic acid copolymers is blended with a thermoplasticpolymer selected from ethylene-α-olefin random copolymers,ethylene-vinyl acetate copolymers, ethylene-(meth)acrylate copolymers,styrene-conjugated diene-styrene block copolymers and hydrogenatedstyrene-conjugated diene-styrene block copolymers.
 4. The melt-blownnonwoven fabric of claim 1, wherein the sum of values of (tensilestrength (g/5 cm))/(basis weight (g/m²)) in machine direction and crossdirection is in the range of from 30 to 100, and each of tensileelongation in the machine direction and the cross direction is 80% ormore.
 5. The melt-blown nonwoven fabric of claim 1, wherein a residualstrain after 50% extension is 20% or less, and a residual strain after100% extension is 50% or less.
 6. The melt-blown nonwoven fabric ofclaim 1, wherein a basis weight is in the range of from 5 to 200 g/m².7. The melt-blown nonwoven fabric of claim 1, wherein said melt-blownnonwoven fabric is embossed.
 8. An elasticized fabric componentcharacterized by comprising a melt-blown nonwoven fabric according toany one of claims 1 to
 7. 9. A packaging material characterized bycomprising a melt-blown nonwoven fabric according to any one of claims 1to
 7. 10. A nonwoven fabric laminate characterized by comprising atleast one layer of a melt-blown nonwoven fabric according to any one ofclaims 1 to
 7. 11. A method of manufacturing the melt-blown nonwovenfabric of claims 1 to 7, in which an ethylene-(meth)acrylic acidcopolymer is melted in an extruder, directly extruded from melt-blowingdies located in a line into two flows of high-speed, high-temperatureconverging air streams, and then the molten copolymer is drawn, madefiner and collected onto a conveying screen, wherein an amount of airflow per one kilogram of said copolymer is in the range of from 10 to200 Nm³ and a distance from melt-blowing dies to a collective screen isin the range of from 10 to 40 cm.